Drill-chuck.



G. W. EMRICK.

DRILL CHUCK. APPLICATION FILED MAY 24, 1912. RENEWED D110. 24, 1913.

Patented July 21, 1914 Wane/.1090

ghoenfoi/ 'rnn srarns ra'rnn'r or GEORGE W. EIVIRICK, OFBROOKLYN,-1\TEIV YORK, ASSIG'NOR, BY MESNE ASSIGNMENTS,

'IO AUTOMATIC DRILL CHUCK CORPORATION,

RATION OF MICHIGAN.

' DRILL-CHUCK.

ice 255.

Application filed. May 24, 1912, Seria1 No. 699,484.

, the art to which it appertains to make and use the'same.

This invention relates to drill chucks, and is an improvement on thatdescribed and claimed in an application for Letters Pat- 'ent of theUnited States, filed by me April 11, 1911, Ser. #620,898, and the objectthereof is to improve the form, construction and operation of the chuckdescribed and claimed in said application, so as to reduce the wear inthe operation thereof and render the same more durable or extend thelife thereof.

The invention described and claimed herein is fully disclosed in thefollowing specification of which the accompanying drawing forms a part,in which the separate drill chuck head and operation, as in said at I)my improved parts of my invention are designated by suitable referencecharacters in each of the views, and in which I Figure 1 is a plan viewof my improved with the chuck shank shownrin section :Fig. 2 a sectionalside view of the drill chuck and showing the chuck shank and a drilltoolin position, and Fig. 3 a plan view of the main casing of the chuck headand showing one of the tumblers in transverse section, and alsoindicating the shank of the drill or drill tool.

In the accompanying drawing I have shown only such parts of the deviceas are necessary to describe my present improvement, and in thefollowing description the parts shown are given the same referencecharacters as in the said application, and said parts are of the sameform, construction application with the exceptions hereinafter pointedout.

In the accompanying drawing I have shown at a an ordinary chuck shankused in connection with devices of this class, and

drill chuck, in the construction of which I provide a chuck headSpecification of Letters Patent.

Patented July 21, 1914:.

Renewed December 24, 1913. Serial No. 808,610.

b an annular cap a body casing, or rotary shell j, and a bottom plate11. In the application referred to, the cap f is secured to the CFDETROIT, MICHIGAN, A;CORPO rotary shell 9', but in this constructionsaid cap and rotary shell are independently rotatable. The bottom plate71 is secured to the bottom of the head 6 by screws 7?, and

formed in the bottom of said head is a central bore 6 which is extendedthrough the bottom-plated and adapted to receive a drill c. l/Vithin'the cap 7 is an annular'ch-amber f in which is placed a helical springlb below which is an annular internal gear g, and mounted around and inthe bottom portion of the head Z2 and in suitable recesses,

not shown herein, are vertically arranged rotary tumblers which arethree in number, and these tumblers are provided'at the tops thereofwith gears c 'which mesh with the internal annular gear 9. The tumblerse are provided with equally spaced annular cam ribs 6 separated bycorresponding annular spaces 6, and the shell j is provided withinternal annular equally spaced ribs j forming corresponding annularrecesses j in which the cam ribs 6 of the tumblers c operate, and allthese parts in connection with others, not shown herein, are of the sameconstruction and operation as in the application hereinbefore referredto, except as to the following modifications or changes thereof. In thisimprovement the cap 7 is held on the chuck head 5 by a ring or band tocountersunk in said cap and secured in place by screws 102 having headscountersunk in the clutch head and in said ring; and a segmental stop iswhich limitsthemovement of the cap f is held in place by a screw 70which connects said stop with the cap f and which is arranged verticallyinstead of radially, as in said application. a

In this improvement instead of forming the imier bearing faces of theannular ribs j of the shell 9' on a continuous circle, as in theapplication referred to, said bearing surfaces are divided intodifferent spaces 9' and i arranged alternately, and formed on the arcsof different circles, the centers of which are at i and j and this givesto the bearing surface of said ribs an undulating or wave like form, andin the operation of the device the cam ribs c of the tumblers a willstrike the shank 0 of the drill or tool 0 at different points on saidcam ribs instead of striking said shank at the same point at all times,and in this way the wear on said cam ribs will be lessened and theduration thereof, or length of time during which said tumblers may beused, will be greatly extended.

From the foregoing description it will be seen that each of the innerbearing surfaces of the ribs 7' of the shell j is divided into sixspaces, of which the alternate spaces are of greater radial dimensionsthan the other three, measured from the center of the clutch head, andthis, while permitting the cam ribs 6 of the tumblers 0 to contact atdifferent points on the shank c of the tool, does not interfere with theoperation of said tumblers.

In assembling the parts, the tumblers are first placed in the head andadjusted into a predetermined position, after which the shell j isslipped on over the head and tumblers from the bottom of the head, afterwhich the bottom plate 6 is secured. in place and the device is readyfor use, all this operation being the same as in the applicationhereinbefore referred to.

It must be understood that the spring 72, one end of which is secured tothe cap and the other to the head, operates to normally hold thetumblers in the operative or locked position, in which position thedrill o is securely held and may be operated by turning the chuck in theusual manner; and it will also be understood that the entire chuckrevolves with the drive shaft, with which, in practice, it is connected,and supposing said shaft should be turned to the right, if it is desiredto release the drill, all that is necessary is to grasp the cap f by onehand. This operation stops the rotation of said cap and holds itstationary; but it will be understood that this grasping of the cap andstoppage of the rotation thereof is only momentary and during the samethe motion of the head 6 of the chuck continues, and through theoperation of the gear 9 on the heads 6 of the tumblers e, the saidtumblers are rotated to the left and the drill 0 is released and may beremoved, as will be read ily understood, and the fact that the shell isrotatable independent of the cap enables the undulating or wave-shapedinner surfaces of the ribs 7' to operate as described in order to securedifierent points of contact between the spiral cams c on the tumblers eand the shank c of the tool when said tool or the shank thereof isinserted into the head of the chuck.

Itmust be understood however, that the cam ribs stoppage of the rotationof the cap j puts the spring 7.: under increased tension and the momentsaid cap is released the said spring turns said cap back to itsoperative position, and the tumblers e are again thrown into theiroperative position.

Having fully described my invention what I claim as new and desire tosecure by Let ters Patent is 1. A drill chuck comprising a head por tionin the central bottom part of which is an axial bore around which aremounted a plurality of detachable and rotary tumblers having spiral camribs on one side thereof, and which do not extend entirely around saidtumblers, a rotary cap mounted on said head and geared in connectionwith said tumblers, a helical spring placed between the rotary cap andsaid head and connected with each, a rotary shell adapted to be passedon over the bottom of said head and sai d tumblers and provided withinternal annular ribs which correspond with and operate in i the spacesbetween said cam ribs, and a bottom plate secured to the bottom of saidhead and holding said shell and tumblers in position, the bearingsurfaces of the cam ribs in said shell being divided into separateparts, of which the alternate parts are formed on an arc of the samecircle, while the other parts are formed on the arcs of circles of lessdiameter.

' 2. A drill chuck comprising a head portion in the central bottom partof which is an axial bore around which are mounted a plurality ofdetachable and rotary tumblers having spiral cam ribs on one sidethereof,

and which do not extend entirely around said tumblers, a rotary capmounted on said head and geared in connection with said tumblers, ahelical spring placed between the rotary ;cap and said head andconnected with each, a rotary shell adapted to be passed on over thebottom of said head and said tumblers and provided with internal annularribs which correspond with and operate in the spaces between said camribs, and a bottom plate secured to the bottom of said head and holdingsaid shell and tumblers in position, said cap and said shell beingindependently rotatable.

3. In a drill chuck of the class described, a head portion in thecentral bottom part of which is an axial bore around which are mounted aplurality of detachable and ro tatable cylindrical tumblers havingspiral on one side thereof and which do not extend entirely around saidtumblers, a rotary shell adapted to be passed on over the bottom of saidhead and said tumblers and provided with internal ribs which correspondwith and operate in the spaces between said cam ribs and bear on thebody of said tumblers, and the bearing surfaces of my invention I havesigned my name in which are divided into separate parts of presence ofthe subscribing Witnesses this which the alternate parts are formed onan 22nd day of May 1912. are of the same circle While the other partsGEORGE W. EMRICK. are formed on the arcs of circles of less WVitnesses:diameter. C. MULREANY,

In testimony that I claim the foregoing as S. ANDREWS.

Copiu of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

